Justification of Ecoregion DelineationThe boundaries are based on "Saso-Fagion crenatae region in Honshu" from Miyawaki (1975) and higher altitude or latitude areas of the Japan Sea floral district from Shimizu (1975), which includes the Oshima peninsula in Hokkaido. The northern boundary corresponds to the Kuromatsunai line between the Hokkaido and Japan Sea floristic districts in Shimizu (1975).